1. Technical Field
The disclosure relates generally to nanotubes, and more particularly to a carbon nanotube yarn and method for making the same.
2. Discussion of Related Art
Carbon nanotubes are tubules of carbon generally having a length of 5 to 100 micrometers and a diameter of 5 to 100 nanometers. Carbon nanotubes can be composed of a number of co-axial cylinders of graphite sheets and have recently attracted a great deal of attention for use in different fields such as field emitters, gas storage and separation, chemical sensors and high strength composites. However, carbon nanotubes are almost never used in microscopic applications at present as it is very difficult to manipulate the carbon nanotubes as a microscopic level. So, assembling carbon nanotubes into macroscopic structures is of great importance to their applications at the macroscopic level.
That a long macroscopic carbon nanotube yarn can be drawn out from a super-aligned carbon nanotube array has been disclosed in U.S. Pat. No. 7,045,108. The carbon nanotube yarn includes a plurality of carbon nanotube bundles that are joined end to end by van der Waals attractive force, and each of the carbon nanotube bundles includes a plurality of carbon nanotubes substantially parallel to each other. Referring to FIG. 7, a simple model of a continued carbon nanotube yarn 14 being drawn out from a super-aligned carbon nanotube array 10 is shown. A number of carbon nanotube bundles 12 are joined end to end by van der Waals attractive force to form the continued carbon nanotube yarn 14. However, in general, the carbon nanotube yarn 14 is several centimeters in length and several microns in thickness. A ratio of surface area to volume of the carbon nanotube yarn 14 is very great, and the surface of it is very clean, so it is very sticky and as such macroscopic level application of the carbon nanotube yarn 14 is restricted to a great extent.
That a long macroscopic carbon nanotube yarn can be drawn out from a super-aligned carbon nanotube array has been disclosed in U.S. Pat. No. 7,045,108. The carbon nanotube yarn includes a plurality of carbon nanotube bundles that are joined end to end by van der Waals attractive force, and each of the carbon nanotube bundles includes a plurality of carbon nanotubes substantially parallel to each other. Referring to FIG. 7, a simple model of a continued carbon nanotube yarn 14 being drawn out from a super-aligned carbon nanotube array 10 is shown. A number of carbon nanotube bundles 12 are joined end to end by van der Waals attractive force to form the continued carbon nanotube yarn 14. However, in general, the carbon nanotube yarn 14 is several centimeters in length and several microns in thickness. A ratio of surface area to volume of the carbon nanotube yarn 14 is very great, and the surface of it is very clean, so it is very sticky and as such macroscopic level application of the carbon nanotube yarn 14 is restricted to a great extent.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate at least one preferred embodiment of the disclosure, in one form, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner.